Siman 103

It is stated in the Gemara (24b): If one was standing in prayer and sneezed, meaning he emitted wind from below—he waits until the odor dissipates, and returns and prays. And to where does he return? If he did not tarry long enough to finish the entire prayer from beginning to end—he returns to the place where he stopped. And if he tarried long enough to finish the entire prayer, according to the Rif and the Rambam, he always returns to the beginning, as I wrote in siman 65, see there. And according to the Tosafot and the Rosh, and the Tur and the Shulchan Aruch, if the odor did not dissipate within this amount of time—he returns to the beginning. But if the odor dissipated beforehand, for indeed it is not common for the odor to tarry that long (and this is the intent of the Magen Avraham, subsection 1, and examine it and you will find it simple), but rather he tarried of his own will long enough to finish the entire prayer—he does not return to the beginning as I wrote there, for whenever he was forced to wait by the law—he returns to the beginning. But if he waited of his own will—he returns to the place where he stopped. (Bach. And also the Magen Avraham does not disagree on this, as the Machatzit HaShekel wrote. And see Pri Megadim.)

If one felt in the middle of the prayer that he needs to emit flatulence from below—he must force himself not to emit it until after the prayer. And there is no concern in this regarding "do not make yourselves detestable," for this only applies to one who delays his bodily needs and not when one delays flatulence (Beit Yosef in the name of Terumat HaDeshen). Furthermore: even if there were a concern in this regarding "do not make yourselves detestable"—it is only a rabbinic prohibition, and they did not decree in such a case where there is an interruption in prayer and a disgrace (see Magen Avraham, subsection 4). And all the more so when he is wearing tefillin, for there is a great prohibition to emit flatulence in tefillin. And this is when he is able to force himself and delay it.

But if he cannot restrain himself and delay and is compelled to pass wind, our sages, of blessed memory, said (ibid.) that he walks backward four amot and releases the wind. And specifically backward, in order to distance himself from the Shekhinah that stands before him (Levush). And it appears that even to the sides it is forbidden, as the distancing is not so recognizable. And it is also simple that if he is in the Shacharit prayer, he is obligated to remove the tefillin beforehand. And after he has passed wind – he stands in his place and waits until the odor dissipates. And he says: "Master of the worlds! You have formed us with many orifices and many cavities. It is revealed and known before You our shame and our disgrace, shame and disgrace in our lives, maggots and worms in our deaths" (Rif). And he returns to his place, and returns to the place where he stopped. And if he delayed long enough to finish the entire prayer, it was explained in section 1. And specifically he returns to his place. But he shall not finish his prayer in the place where he passed wind, for the Shekhinah has already established its place there (Levush). And it seems to me that if he removed his tefillin – he should finish without tefillin, and not interrupt in the middle of the prayer to don them. (And that which regarding urine when it dripped on his knees in siman 78, where they did not require him to say "Master of the worlds," is because there he himself is liable for not checking before the prayer. This is not the case with passing wind – he is under duress. So wrote the Tosafot of R"i. Furthermore: perhaps in this it is a greater disgrace because of the bad odor. And examine carefully and you will find it easy.)

The early authorities wrote that nowadays we do not practice this way, because perhaps they only required this for one who prays in his home. However, in the beit knesset it is a great disgrace to distance himself from his place, and therefore he stands in his place and flatulates. And it follows that he should also not say "Sovereign of the worlds," for when he does not distance himself, his shame and embarrassment are not recognizable (Magen Avraham, subsection 5). And he waits until the odor dissipates, and such is the custom. And it appears to me that he is obligated to remove the tefillin, for it is impossible to permit flatulence in them. And our sages, of blessed memory, said (24b): One who sneezes in his prayer from below—it is a bad sign for him. From above, which is called "nissin"—it is a good sign for him, for just as they cause him satisfaction from below, so they cause him satisfaction from above. For sneezing from above is a pleasure for a person. And know that regarding sneezing from below, there is no difference between flatulence with a sound and without a sound (Magen Avraham, subsection 6 and Eliyah Rabbah, subsection 7). And that which is from below is a bad sign because they distance him from his prayer. But from above there is no interruption here, and there is pleasure in this. And see above, siman 80.